Microscope Seeing Atoms
Name: Bonnie H.
What kind of microscope is used to view atoms? How much
detail is actually seen? Also, could you please explain the indirect
methods of viewing atoms (I am a high school biology teacher, kids are
always asking how scientists see atoms, if at all).
The scanning tunneling microscope has a small probe which actually more like
"feels" the size of the atoms and reads this out on a computer screen. The
probe can pick up individual atoms. IBM used a STM years ago to spell I B M
with uranium atoms and took a picture of it. But one does not actually
directly "see" the atoms.
Peter Faletra Ph.D.
Office of Science
Department of Energy
Scanning-tunneling microscopes and atomic-force microscopes can see
individual atoms. You can look at some images from these and other
microscopes at http://www.physics.purdue.edu/nanophys/images.html.
You don't see much detail, and what you're actually seeing is the
electron cloud. The nucleus is much much smaller.
One indirect method of viewing atoms is protein crystallography, in
which the electron distribution of a complex molecule is inferred from
diffraction patterns of x-rays scattered from a very large number of
identical, aligned molecules in a crystal.
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Update: June 2012